My Activa failed MOT on fast idle emissions

[andmcit]

It's bad on the CO at fast idle = 1.078 with pass under 0.300 and the normal idle is very low 0.043 pass limit 0.500.
In fact CO seemed to get worse with the Second Fast Idle Test at 1.386. The HC is negligible at 8-11 pass limit 200
and lambda is steady at 1.001-1.004 pass limit 0.970-1.030.

When the car started the test it was hunting at idle and unfortunately that's when the readings were taken - by
the end of the test session after 3/4 of an hour it was really a lot happier and smooth but another reading couldn't
be taken and I wonder what the readings would be then.

The car has stood around 8-10 months little used and MrMOTMan suggested new plugs, fresh petrol and additive
injection cleaner with new oil/filters which TBH I was going to do but not specifically for the test now. He didn't
think the cat was suspect and I'm not sure of the validity of swapping everything in sight. MrMOTMan believes the
ECU is constantly tripping things up by resetting itself and altering the fuelling which is the cause of the wide
fluctuating idle and readings so I guess it could be one input feed sensor. The fuel has been allowed to run right
low as I've had it idling loads in the garage whilst messing about with the ride height/ARCS adjustment and new
middle exhaust section so for the test has had £20 quidsworth of regular unleaded. Would Optimax help?

Has anyone encountered a similar issue on their Activa and/or have suggestions on a fix?

[davoxx]

might be dirty fuel if you let it run low. try a full tank of fuel and some injection cleaner and see if she is smoother after a good run.

[CitroJim]

You really need to treat yourself to a Lexia Andrew.. Takes a lot of the guesswork out of an issue like this...

But I'd agree with the garage and Dav... Full service and new petrol as precursor to any further investigation. Plus a good thrash around your lovely countryside...

[dangerousbrian]

Hi, i have the same issue with the CO going all over the place/?
http://www.frenchcarforum.co.uk/forum/v ... =3&t=38148" onclick="window.open(this.href);return false;
I have found if i disconect the battery & reconnect it, the CO levels returns to normal for a while, it did this at the MOT station & it went from a fail on the CO to a pass, i would be interested to know if anyone has fixed the same fault as yours or mine, i have changed the Lambder, no differance, could it be the wiring?